Continental shelf sediments are sinks for dissolved oxygen and sources of many major and minor nutrients required for oceanic surface primary production, resulting in a strong coupling between benthic and pelagic biogeochemical cycling. However, the influence and spatiotemporal variability of benthic remineralization on bottom-water chemistry and the supply of nutrients...
Continental margin sediments have been recognized as a major source of dissolved iron to the global ocean. The focus of this study was to build an early diagenetic model that can be used to simulate iron fluxes from continental margins and thereby identify key controlling factors. The model uses the...
Rotating disc electrodes (RDEs) exploit the induced flushing of a radially spun electrode to increase the overall rate of analyte flux to an electrode sensing surface and its resulting signal current (i). Here initial efforts to evaluate a rotating platinum (Pt) microelectrode for efficacy as a rapid in situ dissolved...
Anoxic sediment overlain by oxic seawater establishes a voltage gradient on the order of 0.7-0.8V across the sediment-water interface. This study follows Reimers et al. (2001) and Tender et al. (2002) who reported the development of a seafloor fuel cell to harvest electrical energy from this potential difference. Prototype fuel...
Rates of benthic O₂ exchange are important measurements for determining organic matter remineralization, and can shed light on factors driving biogeochemical processes in coastal environments. Measurement of in situ O₂ consumption and production within permeable sediments, such as those found over ~43% of the Oregon-Washington shelf, has traditionally been done...
Field deployments, flume experiments, and a 2D wave model have been used to identify the characteristics of Clark-type oxygen microelectrodes and measurement parameters that could possibly bias eddy correlation (EC) flux measurements made under waves. Eddy correlation is a technique adapted from atmospheric sciences that couples concurrent and co-located velocity...
A benthic microbial fuel cell (BMFC) is an electrochemical device that
generates current from the redox gradient at the sediment-water interface. Early
prototypes had anodes buried in anoxic sediments and cathodes in overlying water.
The BMFCs described in this dissertation are based on a chamber design that enables
the use...